The two datasets come with different coastline, different attributes structure (with only one common field: ISO3), and small differences within the content (not all changed sovereignty countries are updated).
Normalization of these two datasets involved:
Intersection: where there is overlap, GAUL wins
gap filling: where there is a gap within the two coastline, this is filled and attributed to the containing EEZ
gaps (yellow) due to different coastline within GAUL (brown) and EEZ (blue)
unification of the attributes structure
identification of Disputed, Joint Managed areas, and attribution to multiple ISO3 codes
identification of the areas not covered by any of the two dataset as Area Beyond National Jurisdiction (ABNJ)
identification of updated information according to ISO 3166-1 standard
dissolve to remove non-unique keys, where present
geometric simplification (topology aware)
JOIN with ancillary information to include additional codes (ISO2 and ISO numeric/UN_M49)
JOIN with ancillary information to get country grouping information (UN_M49 as key).
The result is a dataset with updated geometries and structure, which maintains original source codes (ADM0 for GAUL, MRGID for EEZ).
Marine Ecoregions and Pelagic Provinces of the World (MEOW/PPOW; http://data.unep-wcmc.org/datasets/38 ): biogeographic classification of the world’s coastal, continental shelf, and surface pelagic waters. This dataset combines two separately published datasets:
the “Marine Ecoregions Of the World” (MEOW; 2007)
MEOW
“Pelagic Provinces Of the World” (PPOW; 2012
PPOW
The two datasets come with different attributes structure.
Normalization of these two datasets involved:
Intersection: where there is overlap (MEOW/PPOW comes without coastline), TEOW wins
unification of the attributes structure.
Merged TEOW (green), MEOW (yellow) and PPOW (blue)
Unified BASE Layer
To reduce the number of processing loops to iterate on the WDPA, the two above datasets are merged.
The target is to get, with a single processing cycle, information on:
country
ecoregion
land/marine
all related to the above, as:
number of PAs for country
number of marine/terrestrial PAs for Country
number of PAs for ecoregion
and so on…
Merging of the two datasets involved:
dissolve of the country/eez on country codes (source information, eez or gaul, is discarded; consequently the land/sea information is dissolved in bigger polygons which contains both the objects).
GAUL/EEZ dissolved
Intersect (UNION) of the geometries and attributes of the result from previous step, and ecoregions.
Merged country/ecoregion dataset
Each polygon contained in the resulting dataset contains information on ecoregions (teow, meow,ppow original codes), country (iso3/iso2/un_m49), land/sea (given by teow coastline, which is lower resolution than the GAUL one).
Land (yellow) and marine (brown) information in the country/ecoregion base layer.
Comparison of GAUL coastline (transparent) overlaid on TEOW coastline (green).
Development of a base layer for DOPA.
DOPA spreads indicators based on WDPA dataset, “interrogated” (spatially intersected) by other datasets.
Base datasets for the above process are:
Country boundaries
Sources for this dataset are:
The two datasets come with different coastline, different attributes structure (with only one common field: ISO3), and small differences within the content (not all changed sovereignty countries are updated).
Normalization of these two datasets involved:
The result is a dataset with updated geometries and structure, which maintains original source codes (ADM0 for GAUL, MRGID for EEZ).
Ecoregions boundaries
Sources for this dataset are:
The two datasets come with different attributes structure.
Normalization of these two datasets involved:
Unified BASE Layer
To reduce the number of processing loops to iterate on the WDPA, the two above datasets are merged.
The target is to get, with a single processing cycle, information on:
- country
- ecoregion
- land/marine
- all related to the above, as:
- number of PAs for country
- number of marine/terrestrial PAs for Country
- number of PAs for ecoregion
- and so on…
Merging of the two datasets involved:Each polygon contained in the resulting dataset contains information on ecoregions (teow, meow,ppow original codes), country (iso3/iso2/un_m49), land/sea (given by teow coastline, which is lower resolution than the GAUL one).